Belt



D. C. LIPPMA'NN BELT Fi led llamh 14, 1944 INVENTOR.

DANIEL c. LIF'EMANN. a 4M ATTORNEYS J Patented Mar. 12, 1946 BELT Daniel C. Lippmann, Glenbrook,.Conn., assignor to Celanese Corporation of America, a corporation of Delaware Application March 14, 1944, Serial N 0. 526,389

2 Claims.

This invention relates to the manufacture of belts, and relates more particularly to the manufacture of fabric belts of laminar construction for personal wear,

It is an important object of this invention to provide fabric belts for personal wear of improved construction which will retain their shape under substantially all conditions of use, i. e., will not wrinkle, crease, crush or curl during wear, nor after repeated washings or dry cleanings.

Another object of this invention is the provision of an improved process for making fabric belts which will produce a stiffened, yet flexible belt having substantially smooth surfaces in a simple, expeditious and inexpensive manner.

Other objects of this invention will appear from the following detailed description.

In making fabric belts by prior processes, an insert of canvas coated with an adhesive is normally employed to stiffen the belt and to maintain the same in desired shape. However, the adhesive coating on the insert tends to flake off and wash away in laundering with the result that the belt loses its desired stiffness and appearance. Moreover, in making prior fabric belts, the outer or covering fabric of the belt enclosed the canvas insert in such a manner that the edges of the covering fabric met or overlapped each other on the inner surface of the belt, usually in the center of said surface, causing an unsightly seam or ridge. When a ridge was formed by the union of the edges of the covering fabric, pressing of the belt caused the ridge to form a mark on the opposite or exposed surface. I

In accordance with the present invention, I produce a belt which will be free from the above noted and other disadvantages by employingan insert containing a thermoplastic material such as cellulose acetate or other organic derivative of cellulose, and by joining the longitudinal edges of the covering fabric in such a manner that together they form an edge of the finished belt,

Thus, in manufacturing the fabric belts in accordance with the process of my invention, a strip of fabric of predetermined length and width, and of wool, cotton, linen, natural silk, regenerated cellulose, cellulose acetate or any other material, is folded along its longitudinal axis and a strip of fabric having a basis of a thermoplastic material of substantially the same size and shape as the covering fabric strip, but of lesser width than the outer fabric folded, is inserted in the fold. The assembly is then passed through a suitable sewing machine having a folding attachment where the free longitudinal edges are turned inside the tic fibers.

fold and sewn together, the stitches passing through the insert if desired. The assembly is then subjected to the action of heat and pressure, in the presence or absence of moisture, to cause the thermoplastic insert to be coalesced to the inner surface of the covering fabric to form a substantially unitary laminated structure, This laminating process also effects the desired stiifening of the belt material.

An important advantage of this invention is that the assembly of fabrics employed as starting material may first be cut, sewn or otherwise shaped quite readily, since they have the proprties of and may be handled as ordinary fabrics. After the belts are formed, they may be treated with the liquid that aids in effecting the coalescence of the cellulose acetate fabric after exposure to elevated temperatures and thensubjected to heat and pressure to impart the desired stiffness and adhesion of the layers. In this man ner, the sewing of stiff material is avoided.

Belts made in accordance with this invention have any desired degree of stiffness, which is relatively permanent, so that they may be subjected to repeated-laundering without losing their stiffness to any appreciable degree. In this manner, the use of starch or other extraneous stiffening materials during laundering is obviated.

This invention ma be carried out in a large number of ways, particularly as to the nature of the fabric or fabrics employed, provided that cellulose acetate in any form, such as powder, yarns or filaments, is present in at least one of the fabrics employed.

If the cellulose acetate is present in the form of yarns or filaments, then there should be present in the belt at least one layer of fabric, which either consists WhOlly of cellulose acetate yarn, or which is a mixed fabric containing yarn of cellulose acetate either in the warp or in the weft or both, in any desired degree of alternation, with yarns of other non-thermoplastic fibers such as cotton, regenerated cellulose, linen, wool or natural silk. This alternation may be, for instance, 1, 2, 3, or more cellulose acetate yarns with 1, 2, 3, or more yarns of cotton or other non-thermoplas- For convenience, the warp may be made with such alternation of cellulose acetate yarn and yarn of other fibers, while the weft may consist wholly of such cellulose acetate yarn or wholly of yarn of other fibers. However, the weft may consist of an alternation of such cellulo-se acetate yarns and non-thermoplastic yarns of other fibers, in which case, if the fabric is made in ordinary looms, the alternations will be preferably in twos or multiples of twos. If desired, a fabric may be used in which either the warp or the weft consists wholly of cellulose acetate yarn while the other component consists of non-thermoplastic yarn.

In its preferred form, my invention contemplates the use of an insert comprising a woven fabric made of or containing yarns, filaments and fibers of cellulose acetate, However, instead of employing a woven fabric, a knitted or netted fabric may be employed. Also, a fabric containing mixed yarn containing both filaments of cellulose acetate and fibers of cotton or other nonthermoplastic material may be employed.

As indicated, an insert comprising a single layer of fabric consisting wholly of cellulose acetate yarn or a single layer of any of the fabrics, above described containing both cellulose acetate yarn or filaments and non-thermoplastic fibers is preferably employed in accordance with this invention, whereby a relatively thin fabric belt having the desired degree of stiffness may be produced. Alternatively, 2, 3, 4 or more of such inserts may be treated with the liquid that causes stiffening at elevated temperatures and heat and pressure applied to the whole surface to form a heavier insert and belt.

In another, and in some cases preferred, method of carrying out the invention, the insert comprising one or more fabrics consisting whollyof non-thermoplastic yarns, such as cotton, linen, reconstituted cellulose, wool or silk, assembled with one or more fabrics consisting wholly of cellulose acetate yarn or of a mixture of cellulose acetate yarn and filaments and yarn of non-thermoplastic fibers, as above described, is assembled and coalesced. Such an insert is also employed in making heavier belts.

In another form of my invention I may employ, as the insert of the belt assembly, or as the sheet material which is to be coalesced to bind the other sheets together, a fabric consisting wholly of non-thermoplastic yarns and filaments which has been coated with cellulose acetate. This coating of cellulose acetate may be applied to the non-thermoplastic material by applying the same thereto in the form of a powder or as a slurry in a liquid carrier. The coating of cellulose acetate may also be applied to the non-thermoplastic fabric from a solution of the cellulose acetate in a volatile solvent therefor, which volatile solvent is permitted to evaporate prior to laminating the fabrics.

If desired, either the yarns or powder coating that contains cellulose acetate also may contain a white or colored pigment. For instance, titanium oxide, antimony oxide, lead oxide or carbonate. iron oxide, etc, may be added to the cel lulose acetate. When white pigments ar employed with the cellulose acetate, the product is whiter in color and is not glazed or shiny in appearance.

As instance of the manner that the various fabrics comprising the belt may be assembled, the following are given. In the case of a belt where an exterior of cotton or linen is desired, an insert comprising fabric consisting wholly of or containing cellulose acetate yarn, as above described, may be 'mterposed between the folded covering fabric consisting of cotton, wool, linen or other nonthermoplastic fibers.

Where the covering fabric of the belt is made of or containing cellulose acetate, the insert may comprise a fabric consisting wholly of non-thermoplastic fibers. In this case the fabric of nonthermoplastic material may be of the desired construction to impart to the finished belt such properties as may be required.

These arrangements are given only by way of example, it being obvious that other arrangements with an insert made of any number of layers of fabric may be employed to obtain any desired efiects.

The assembly of fabrics comprising the belt is, in accordance with this invention, treated with a liquid that acts on the cellulose acetateat elevated temperatures so as to cause the same to stiffen, but which is preferably not an active solvent at ordinary temperatures. For this purpose, it is preferable to compound a liquid by mixing together an alcoholic materia1 having a relatively low boiling point which alcoholic material is a solvent for the cellulose acetate at elevated temperatures, and a lasticizer for the cellulose acetate. To the mixture of plasticizer and alcohol may be added Water as desired. The plasticizer mayor may not be soluble in the alcohol or alcohol/water mixture. The plasticizer may be dissolved in the low boiling alcohol or be added thereto as a suspension. Small amounts of active solvents, for instance, acetone, may be added to the liquid.

As the alcohol constituent in the liquid that acts on the cellulose acetate at elevated temperatures, I prefer to use methyl alcohol, ethyl alcohol, isopropyl alcohol and the like. Mixtures of these alcohols may be employed or mixtures of one or more of these alcohols with water may be used as one component of the medium that acts on the cellulose acetate at elevated temperatures. The percentage of alcohol in the liquid may vary within wide limits, however, it is preferable to employ more than 50% alcohol.

Aqueous solutions of ethyl, methyl or isopropyl alcohol of 55 to 90%, particularly of about concentration are very useful for this purpose. An aqueous solution of the mono methyl ether of ethylene glycol containing say about 20 of water may be substituted for all or a part of the alcohol employed in forming the liquid having effect on cellulose acetate at elevated temperatures.

The plasticizer employed admixed or dissolved in the alcohol or alcohol and water may be'any suitable one for the particular cellulose derivative or mixture of cellulose derivatives employed in the intermediate layers of the fabric, which intermediate layers are to be coalesced for the purpose of uniting the assembly. The plasticizers may be any of the high boiling solvent or softening agents as, for example, the aryl sulphonamides such as para ethyl toluol sulphonamide, the alkyl phthalates such as dimethyl phthalate, the dialkyl tartrates such as dibutyl tartrate, the alkoxy esters of polybasic organic acids such as diethoxy ethyl phthalate, the polybasic acid esters of the mono. alkyl ethers of polyhydric alcohols such as diethylene glycol ethyl ether ester of phthalic acid, the alkyl esters of phosphoric acid such as triethylglycol phosphate, the aryl esters of phosphoric acid such as tricresyl phosphate, the mixed alkyl and aryl phosphates such as ethylglycol dicresyl phosphate, and camphor. Other high boiling plasticizers such as triacetin, diacetin, etc., may be employed. The expression high boiling as employed herein is intended to mean boiling above 200 C.

The liquid employed as an aid in coalescin the cellulose acetate fabric may be applied to the assembly of fabrics in any suitable manner, such as by dipping, spraying, padding or brushing. A

convenient manner of wetting the assembly is by padding the same with the liquid. Preferably, both sides of the assembly should be wetted with the liquid, as it is desirable that all of the layers of the fabric, present be wetted therewith when heat and pressure is applied.

The so-wetted assembly of fabrics is subjected to heat and pressure. This may be done by any suitable device as, for instance, by hot ironing or by passing between pressure rolls, one or both of which are heated, or between a heated roller and a heated or cold plate or surface, or between a heated pressing iron or plate and a cold board or surface. The heating device may be heated to the desired temperatures, for instance, 100 to 180 C. or more, and the pressure applied may be of any desired degree as, for instance, from to 600 pounds per square inch.

Where the covering fabric of the belt comprises cellulose acetate, heated devices that have desired designs, such as stripes, dots, rectangles or other geometric figures, and floral or other designs, embossed thereon may be employed to produce novel effects on the exposed portion of the belt. Since the alcohol and like liquids are not solvents for the cellulose acetate at ordinary temperatures, only those portions of the belt that come in contact with the embossed portions of the heated device become stiffened and/or united, while the other portions retain the properties of the original fabric. This local application of heat and pressure may be done by manually operated means if desired.

The belts made in accordance with this invention may be made more or less stiff as desired by dered softer by the incorporation of plasticizers, i

such as diethyl phthalate, dimethyl phthalate,

dibutyl tartrate, etc., in the aqueous alcohol or onto or in the component fabric containing the cellulose acetate filaments or yarns.

In order to describe my invention more fully,

reference is had to the accompanying drawing, wherein Figure 1 is a perspective view, partly in section, of a belt made in accordance with my invention;

Figure 2 is a perspective View of the assembly of the fabrics comprising the covering fabric and insert, and

Figure 3 is also a perspective view of the assembly after it has been processed by folding the edges and by stitching the same.

Like reference numerals indicate like parts throughout the several views of the drawing.

Referring to the drawing, the belt generally indicated by reference numeral 4 is made from a strip of covering fabric 5 of the desired dimensions and which may be of wool, cotton, linen, natural silk, regenerated cellulose, cellulose acetate or other synthetic material, folded along its longitudinal axis 6 and is so shaped that when folded forms a point I. The other end of the belt is generally not shaped into the form of a point and has sewn thereto the belt buckle 8, as is well understood in the art. A strip of fabric 9, which has a basis of a thermoplastic material, is placed in the fold of the covering material 5. The assembly is passed through a sewing machine having a folding attachment which turns the edges into the fold as shown at H in Figure 3, one of the turned edges acts to retain the strip 9 in position. The sewing of the edges as shown by stitches l2 takes place substantially simultaneously with the folding of the edges. The assembly is now ready to be subjected to the laminating process, wherein the coalescence of the component parts of the assembly takes place, in accordance with the processes outlined above.

While this invention has been described particularly in connection with yarns containing filaments or fibers having a basis of cellulose acetate, such cellulose acetate yarns or fibers may be replaced in whole or in part by other esters of cellulose, such as cellulose propionate and cellulose butyrate, or yarns or fibers of ethers of cellulose, such as ethyl cellulose and benzyl celluose, or yarns or fibers of synthetic resins or synthetic linear polyamide condensation products, such as polyamides derived from amino acids, or from the condensation of diamines with dicarboxylic acids,

7 in which case suitable liquids having required properties for aiding coalescence under heat and pressure will be selected.

It is to be understood that the foregoing detailed description is given merely by way of illustration and that many variations may be made therein without departing from the spirit of my invention.

Having described my invention, what I desire to secure by Letters Patent is:

1. A belt for personal wear, comprising a covering fabric folded along the length thereof and having turned in longitudinal edges sewn together, and a fabric layer within said folded covering fabric and within at most one of said turned in edges, saidfabric layer containing thermoplastic material effecting coalescence of said covering fabric and said fabric layer and causing said belt to be relatively stiff and free from the tendency to wrinkle or curl.

2. A belt for personal wear, comprising a covering fabric folded along the length thereof and having turned in longitudinal edges sewn together, and a fabric layer within said folded covering fabric and within at most one of said turned in edges, said fabric layer containing cellulose acetate effecting coalescence of said covering fabric and said fabric layer and causing said belt to be relatively stiff and free from the tendency to wrinkle or curl.

DANIEL C. LIPPMANN. 

